Machinability study and process optimization of drilling and milling in two types of CFRP plates

To compare the machinability of various types of carbon fiber reinforced polymer (CFRP) materials, drilling and milling experiments are conducted on two types of CFRP sheets. Epoxy-based T700 carbon fiber reinforced and bismaleimide-based T800 carbon fiber reinforced. The pattern and size of machining-induced damage under each condition are observed and compared with a digital microscope. Experiments of parameters matrix with cutting speed and feed per turn as variables were carried out to reveal the influencing factors of machining quality under different processes. The results show that different CFRP plates have similar damage patterns in drilling and milling processes, but have some differences in specific damage patterns and delamination tearing tendency. In hole making, the machining quality is greatly affected by each turn feed, while in milling, the machining quality is more significantly affected by the cutting speed.The relationship between machining parameters and machining quality was established by regression analysis of experimental data. The optimal machining parameters were obtained by using the optimization algorithm for the optimal machining quality, namely the minimum machining damage and the balance of mass efficiency. The optimum processing parameters are obtained and verified by experiments.